In the production of a packages of objects such as tablets, capsules, pills, or the like the objects are typically delivered to the packaging machine in bulk form. First they are separated and arrayed in a holder in rows and columns, normally with a single object in a respective pocket formed in a plate in a pickup station. From here a group or batch of the objects are picked up by a suction grab that transfers them to upwardly open blisters of a packaging-foil strip that is moved continuously past the pickup station. This transfer apparatus, which is the subject of the instant invention, must therefore work quickly, picking up and dropping large numbers of small objects with great accuracy. The product being packaged is often relatively valuable and any empty blisters will require an entire package to be culled out, so the machine must function without failure for a long production run. Downstream of the transfer device a cover foils is typically laminated atop the blister foil, and the two foils are cut up into packages and further prepared for distribution.
In most systems the grab is a large suction grab plate with an array of downwardly open suckers. This plate is swung in an arc between a position above the pickup station where each sucker is aligned above with a respective object-holding pocket and a position over the passing strip where each sucker is aligned above a respective blister. When above the strip the grab must move in a straight line parallel to the travel direction of the strip at least during the time when the suction is cut and the objects are dropped into the blisters. Thus the grab plate moves through an arcuate path from the pickup station to above the strip, then in a straight line with the strip, although it can move wholly arcuately on the way back to the pickup station. Such compound movement is very hard to do.
Such a generic apparatus is described in German patent 10 2005 007 532 of J. Matzenmuller. The disadvantage associated with this apparatus is that rotation of the transfer unit about the slide axis, which is not a function of the rotary displacement of the pivot arm about the support axis, and radial displacement of the transfer unit relative to the support axis are accomplished with several different drives mounted right on the movable parts. The structure is complex and fairly massive, so that it moves relatively slowly.
Other systems described in EP 1,072,516 of M. Spataforo, EP 1,342,666 of B. Tonnigs, GB 2,172,257 of W. Hogenkamp, and U.S. Pat. No. 5,934,859 of B. Goetzelmann are similarly complex, massive, and slow.